Spring MVC Jaxb2Marshaller无法正确处理继承类

Question

I have a Spring MVC controller to generate XML, it generates regular objects without any problem. However, looks like it does not support polymorphism properly. I guess it might be configuration issue.

Here is my class hierarchy.

abstract class Base {
   String attr1;
}

class Child1 {
   String attrChild1;
}

class Child2 {
   String attrChild2;
}

@XmlRootElement
class MyList {

   @XmlElement (name="list")
   List<Base> lists;
}

Then I add 1 instance of Child1 and one instance of Child2 into lists.

If I manually use JAXB to marshall it, it will generate some XML like this

<list xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="child1">
  <attr1>...</attr1>
  <attrChild1>...</attrChild1>
</list>
<list xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="child2">
  <attr1>...</attr1>
  <attrChild2>...</attrChild2>
</list>

However, if I go through spring, I will only get

<list>
  <attr1>...</attr1>
</list>
<list>
  <attr1>...</attr1>
</list>

Any suggestions?

Here is my controller class

@RequestMapping(value="/rest/test", method=RequestMethod.GET, produces="application/xml")
public @ResponseBody MyList getMyList() {
      MyList myList = ....;
      // add instance of Child1/2
      return myList;
}

Answer 1

Try adding:

@XmlSeeAlso({Child1.class, Child2.class})
abstract class Base {
}